Blockchains are aggregated and distributed databases: shared, chained, and immutable registries that conflate the production of digital tokens with their circulation. At their most basic level, they are technologies for keeping account, or records, of some form of activity, hence they are part of a long lineage of storing data, from clay tablets to bookkeeping. On a technical level, blockchains are peer-to-peer (P2P) structures for distributing and storing data. This chapter begins with a historical consideration of the emergence of peer production, including a reevaluation of the work of Yochai Benkler. It shows that peer production was given coherence as a model of production by being contrasted with two other modes (hierarchies and markets) and through the lens of Benkler's economic liberalism. The chapter distinguishes between four moments or aspects of blockchain initiatives that configure peers in different ways: peer production, peer development, peer governance, and peer exchange.